Opportunistic viral Infections Flashcards
What are endogenous and exogenous viruses?
- ‘Endogenous’
Latent viruses that reactivate in absence of immune system
Acquired in past prior to immune suppression e.g. Varicella Zoster - ‘Exogenous’
Viruses acquired from environment
increased severity in immunosuppressed e.g. Influenza, SARS-CoV-2 - Symptomatology may be altered vs. healthy
What are the AIDS defining illness: viral causes?
Describe the Baltimore classification
How do we detect viruses?
•Viruses are challenging to grow- requiring human cells & dangerous
- Therefore we look for indirect or direct evidence of their presence
- Indirect detection: response of the immune system to the virus•
- These tests are useful to see if you have ever had the infection•
- Direct detection: fragments of the actual virus
- Viral proteins (lateral flow/antigen tests)
- Viral genetic material (the virus genetic material present with patient sample•Polymerase chain reaction•
- These tests are useful to see if you have the infection now
Describe serology.
- Measure levels of antibody in patients serum•
- +++ IgM indicate Active or Resolving infection
- +++ IgG indicates past infection > 6 weeks ago
- •Antibody levels ↓↓↓ reduced in Immunosuppressed• - may lose antibodies
- Serological course may differ depending upon virus
Describe the use of PCRs
- Polymerase chain reaction•
- Detect viral genome in samples via amplification•
- Highly sensitive and specific•
- Performed on many different sample types•
- Viral load can be used to monitor infection•
- May remain positive after infection resolved
What is the diagnostic test we use when immunocompromised
•Immune system = non functional → Serology - cant be done
1.Screen prior to immunosuppression
- Identify previous viral exposure that may reactivate
- Guide the use of antiviral prophylaxis•
2.Monitor using PCR
- Identify viral reactivation promptly → Rx
- Detect infection
- Approach is performed by protocol
What are the diagnostic protocols in immunosuppressed?
HEV PCR
What is the relative risk of opportunistic viral infection?
What is the transplant immunosuppression timeline?
What are the sources of viral infections in transplant recipients?
Allogeneic Stem cell transplant
What infections do we screen for with molecular testing?
What are the features of anti-viral therapy in the immunosuppressed?
- Therapeutically challenging
- Pre-emptive treatment
- Prophylaxis
- Increased doses
- Longer duration
- Combination therapy
- ↑ Opportunity antiviral resistance
- ↑ Toxicity of antivirals
What are the issues with HSV 1 & 2 infection and how do we manage them in the immunocompromised?
What does VZV cause in immunosuppresed?
How do we prevent and manage VZV infections?
HSV PCR
What does post-transplant lymphoproliferative disease (PTLD) predispose to? How can we confirm it?
What are the issues and management of EBV infections in immunosupression?
What are the issues and management of CMV in the immunosuppressed?
What are the manifestations of CMV infection?
How does CMV infection differ between solid organ transplants and haemotopoietic stem cell transplant?
What are the CMV prevention strategies post-transplant?
What is CMV treatment?
Rituximab - anti B cell mAb
What is the John Cunningham virus? What does it cause? Who do we see it in?
Describe progressive multifocal leukoencephalopathy. How do we diagnose it?
What is BK virus?
What respiratory viruses do we see in the immunocompromised?
Which of the Hepatitis viruses do we worry about?
What can happen in hepatitis B infections in the immunocompromised? How do we prevent them?
What are the markers of disease and immunity in Hep B ?
Describe the risk of HBV reactivation and how we prevent it?
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